Allergy Immunology and Cell Biology Unit, Department of Immunology and Molecular Medicine, Faculty of Medical Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka.
MRC Translational Immune Discovery Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK.
J Biomed Sci. 2024 Sep 4;31(1):86. doi: 10.1186/s12929-024-01077-8.
While dengue NS1 antigen has been shown to be associated with disease pathogenesis in some studies, it has not been linked in other studies, with the reasons remaining unclear. NS1 antigen levels in acute dengue are often associated with increased disease severity, but there has been a wide variation in results based on past dengue infection and infecting dengue virus (DENV) serotype. As NS1 engages with many host lipids, we hypothesize that the type of NS1-lipid interactions alters its pathogenicity.
Primary human monocyte derived macrophages (MDMs) were co-cultured with NS1 alone or with HDL, LDL, LPS and/or platelet activating factor (PAF) from individuals with a history of past dengue fever (DF = 8) or dengue haemorrhagic fever (DHF = 8). IL-1β levels were measured in culture supernatants, and gene expression analysis carried out in MDMs. Monocyte subpopulations were assessed by flow cytometry. Hierarchical cluster analysis with Euclidean distance calculations were used to differentiate clusters. Differentially expressed variables were extracted and a classifier model was developed to differentiate between past DF and DHF.
Significantly higher levels of IL-1β were seen in culture supernatants when NS1 was co-cultured with LDL (p = 0.01, median = 45.69 pg/ml), but lower levels when NS1 was co-cultured with HDL (p = 0.05, median = 4.617 pg/ml). MDMs of those with past DHF produced higher levels of IL-1β when NS1 was co-cultured with PAF (p = 0.02). MDMs of individuals with past DHF, were significantly more likely to down-regulate RPLP2 gene expression when macrophages were co-cultured with either PAF alone, or NS1 combined with PAF, or NS1 combined with LDL. When NS1 was co-cultured with PAF, HDL or LDL two clusters were detected based on IL10 expression, but these did not differentiate those with past DF or DHF.
As RPLP2 is important in DENV replication, regulating cellular stress responses and immune responses and IL-10 is associated with severe disease, it would be important to further explore how differential expression of RPLP2 and IL-10 could lead to disease pathogenesis based on NS1 and lipid interactions.
虽然登革热 NS1 抗原已被证明与一些研究中的疾病发病机制有关，但在其他研究中并未与之相关联，其原因尚不清楚。登革热急性期的 NS1 抗原水平通常与疾病严重程度增加有关，但基于过去的登革热感染和感染的登革热病毒（DENV）血清型，结果存在很大差异。由于 NS1 与许多宿主脂质结合，我们假设 NS1-脂质相互作用的类型改变了其致病性。
原代人单核细胞衍生的巨噬细胞（MDM）与 NS1 单独或与来自有过去登革热病史（DF=8）或登革出血热（DHF=8）个体的高密度脂蛋白（HDL）、低密度脂蛋白（LDL）、脂多糖（LPS）和/或血小板激活因子（PAF）共同培养。测量培养上清液中的白细胞介素 1β（IL-1β）水平，并在 MDM 中进行基因表达分析。通过流式细胞术评估单核细胞亚群。使用欧几里得距离计算进行层次聚类分析以区分聚类。提取差异表达变量，并开发分类器模型以区分过去的 DF 和 DHF。
当 NS1 与 LDL 共同培养时，培养上清液中的 IL-1β 水平显着升高（p=0.01，中位数=45.69pg/ml），而当 NS1 与 HDL 共同培养时，IL-1β 水平降低（p=0.05，中位数=4.617pg/ml）。当 NS1 与 PAF 共同培养时，过去患有 DHF 的人产生的 MDMs 中 IL-1β 水平更高（p=0.02）。当巨噬细胞与 PAF 单独或 NS1 与 PAF 联合或 NS1 与 LDL 联合共培养时，过去患有 DHF 的个体的 MDMs 中 RPLP2 基因表达明显下调。当 NS1 与 PAF、HDL 或 LDL 共同培养时，根据 IL10 表达检测到两个聚类，但这些聚类不能区分过去患有 DF 或 DHF 的个体。
由于 RPLP2 对 DENV 复制很重要，可调节细胞应激反应和免疫反应，IL-10 与严重疾病相关，因此进一步探索 NS1 和脂质相互作用如何导致基于 RPLP2 和 IL-10 的差异表达导致疾病发病机制非常重要。
